The 1986 Pittsburgh Pirates season was the 105th season of the Pittsburgh Pirates franchise; and their 100th in the National League. This was their 17th season at Three Rivers Stadium. The Pirates finished sixth and last in the National League East with a record of 64–98. This was also the rookie season of left fielder Barry Bonds, who led the Pirates with 36 stolen bases and finished second on the club with 16 home runs.

Batting

Note: G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in

Pitching

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

• Barry Bonds, Led all rookies in home runs (16)

1986 Major League Baseball All-Star Game

• Tony Peña, C, reserve
• Rick Rhoden, P, reserve

• December 10, 1985 – Bobby Bonilla drafted by the Chicago White Sox in the 1985 rule 5 draft.
• December 10, 1985 – Bip Roberts drafted by the San Diego Padres in the 1985 rule 5 draft.
• December 15, 1985 – Purchased Matias Carrillo from Poza Rica (Mexican).
• January 14, 1986 – Drafted Moisés Alou in the 1st round (2nd pick) of the 1986 amateur draft (January). Player signed May 23, 1986.
• January 14, 1986 – Drafted Archi Cianfrocco in the 11th round of the 1986 amateur draft (January), but did not sign the player.
• February 13, 1986 – Signed Ed Farmer as a free agent.
• April 1, 1986 – Traded Chris Green to the California Angels. Received Kevin Davis (minors).
• April 3, 1986 – Traded Marvell Wynne to the San Diego Padres. Received Bob Patterson.
• April 4, 1986 – Released Johnnie LeMaster.
• April 4, 1986 – Released Sixto Lezcano.^[4]
• April 4, 1986 – Traded Jason Thompson to the Montreal Expos. Received players to be named later. The Montreal Expos sent Ben Abner (minors) (April 7, 1986) and Ronnie Giddens (minors) (April 7, 1986) to the Pittsburgh Pirates to complete the trade.
• April 24, 1986 – Signed U.L. Washington as a free agent.
• May 1, 1986 – Released Ravelo Manzanillo.
• May 8, 1986 – Released Steve Kemp.
• June 2, 1986 – Drafted Jeff King in the 1st round (1st pick) of the 1986 amateur draft. Player signed July 10, 1986.
• June 2, 1986 – Drafted Mike Walker in the 2nd round of the 1986 amateur draft.
• June 2, 1986 – Drafted Scott Ruskin in the 3rd round of the 1986 amateur draft (June Secondary).
• June 2, 1986 – Drafted Archi Cianfrocco in the 4th round of the 1986 amateur draft (June Secondary), but did not sign the player.
• June 2, 1986 – Drafted Tom Goodwin in the 6th round of the 1986 amateur draft, but did not sign the player.
• June 2, 1986 – Drafted Tony Longmire in the 8th round of the 1986 amateur draft.
• June 2, 1986 – Drafted Stan Belinda in the 10th round of the 1986 amateur draft. Player signed June 5, 1986.
• June 2, 1986 – Drafted Keith Shepherd in the 11th round of the 1986 amateur draft. Player signed June 28, 1986.
• June 2, 1986 – Drafted Tommy Shields in the 15th round of the 1986 amateur draft.
• June 2, 1986 – Drafted Jeff Banister in the 25th round of the 1986 amateur draft.
• June 2, 1986 – Drafted Rick Reed in the 26th round of the 1986 amateur draft. Player signed July 2, 1986.
• June 2, 1986 – Drafted Mike Mordecai in the 33rd round of the 1986 amateur draft, but did not sign the player.
• July 13, 1986 – Signed Willie Smith as an amateur free agent.
• July 23, 1986 – Released Lee Mazzilli.
• July 23, 1986 – Traded José DeLeón to the Chicago White Sox. Received Bobby Bonilla.
• July 30, 1986 – Signed Julio Peguero as an amateur free agent.
• September 30, 1986 – Traded Jeff Zaske to the Texas Rangers. Received Randy Kramer.
• October 11, 1986 – Signed Mike York as a free agent.
• October 15, 1986 – Trench Davis granted free agency.